Breathable and highly sensitive self-powered pressure sensors for wearable electronics and human-machine interaction

Abstract

Self-powered pressure sensors have gained significant attention for their transformative potential in wearable electronics, Internet of Things (IoT) devices, and artificial e-skins. However, attaining high sensitivity while maintaining good breathability has proven to be a formidable challenge. In this study, we design a hierarchically structured all-nanofiber self-powered pressure sensor utilizing the triboelectric and electrostatic induction principles. The sensor is fabricated via an electrospinning process and consists of a multi-layered architecture comprising nanofiber membranes (NMs): a polyvinylidene fluoride/graphene NM as the negative friction layer, an ethyl cellulose/polyvinyl polypyrrolidone NM as the positive friction layer, and silver nanowire-loaded polyurethane NMs as the electrode layers. This innovative all-nanofiber design not only ensures remarkable breathability but also achieves outstanding sensitivity (15.91 V/kPa) and low detection limits (0.0044 N and 1°), attributed to the enhanced surface roughness and amplified surface charge potential of the friction layer. The sensor demonstrates its versatility by accurately monitoring various human motions and performing dual-language character recognition (Chinese and English), highlighting its vast potential for applications in wearable electronics, human-machine interaction, and next-generation e-skins.